2016-10-08_REVISION - M1977300 - Laserfiche WebLink

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COTTER CORPORATION (N.S.L.) SCHWARTZWALDER MINE, GOLDEN, COLORADO PERMIT NO. M-1977-300 RESPONSE TO COMMENTS REGARDING TECHNICAL REVISION 23 (TR-23) July 20, 2016 Comment Letter Comment No. 1 - The excavation of alluvial fill will occur near areas which have been designated as critical habitat for the Preble's meadow jumping house (PMJM). Section E-4. 1 of Amendment No.4 states that excavation within the PMJM habitat will require permits with the U.S. Fish and Wildlife Service and/or the U.S. Army Corps of Engineers. Please clarify if excavation of alluvial fill will occur within the designated habitat of the PMJM. If so, commit to obtaining the necessary permits and providing copies to the Division prior to excavation activities. RESPONSE: Excavation of the proposed Phase 2 alluvial fill will directly and indirectly impact 15.89 acres of designated Preble's meadow jumping mouse ("PMJM") critical habitat. This determination is based on both proposed permanent and temporary impacts to both previously disturbed and undisturbed PMJM upland habitat and previously disturbed PMJM riparian habitat. Of the proposed 15.89 acres of direct and indirect impact to existing habitat at the Site, 6 acres of impact will occur on heavily disturbed upland areas that are not currently suitable PMJM habitat, but are within the 394-ft PMJM habitat setback estimation. The remaining 9.89 acres of habitat impacts include 8.05 acres of permanent direct impact to both previously disturbed and undisturbed upland habitat, 1.24 acres of permanent direct and indirect impact to riparian habitat, and 0.6 acres of permanent direct impact to creek bed. Cotter is currently obtaining a Section 404 Nationwide Permit(NWP #38 for Cleanup of Hazardous Wastes) from the U.S. Army Corps of Engineers ("USACE") for this proposed Phase 2 work due to potential creek impacts. USACE is in consultation with the U.S. Fish and Wildlife Service(USFWS) as part of this permitting process Cotter expects to receive the USACE/USFWS permit by I/1/2017. Comment No. 2 - Cotter has proposed to import 33,000 cubic yards of material to backfill the alluvial fill excavation. Pursuant to Hard Rock Rule 3.1.5(9)(c),the Operator shall provide a signed affidavit certifying that the material is clean and inert, as defined by Rule 1.1(24),In addition, specify if this material will come from a permitted mine site, and if so, specify the DRMS File Number. Response: Backfill will occur at the end of the project after Cotter is confident that no more excavation is needed. The decision to proceed with backfill will be done in concert with the Division. Cotter agrees to supply an affidavit confirming any imported fill material is clean and inert. Additionally, should any imported fill come from a mine site, Cotter will provide the Division with the appropriate DRMS File Number. Cotter assumes that 33,000 cubic yards of backfill material is a"maximum" estimate.